Ignition coil and terminal connector



y 1942- w. E. SCHWARZMANN arm. 2,281,862

IGNITION COIL AND TERMINAL CONNECTOR THEREFOR Filed Oct. '7, 1941 TO HIGH TE MSION D16 TRIBU TOR ATTORNEY Patented May 5, 1942 IGNITION COIL AND TERMINAL CONNECTOR THEREFOR Wolfgang E. Schwarzmann, Longmeadow, and Charles Strniste, Agawam, Masa, assignors to American Bosch Corporation, Mass, a corporation or New York Springfield,

Application October 7, 1941, Serial No. 413,958

6 Claims.

This invention relates to ignition coils for use in electrical ignition systems for internal combustion engines, and also to such coils in combination with terminal connectors therefor, whether the coil is part of a magneto or a battery system, and whether the connector is a part oi an automatic short circuiting arrangement for the magneto or for connecting a switch, vibrator or other electrical deviceto the coil of the magneto or battery system. A general type of automatic disabling arrangement is disclosed broadly in U. S. Patent 2,253,201 but is there disclosed specifically in connection with the live terminal of the mechanical interrupter of the ignition generator, and this general type of coil is disclosed broadly in U. 8. Patent 2,259,229 but that discloses no provision for a terminal connector in combination therewith for any purpose.

It has been found that it is sometimes inpractical if not impossible for mechanical reasons, on account of space requirements, interferences or otherwise, to provide a terminal connector of this kind in association with the inter rupter of the magneto, or with the timer-distributor used with the coil of a battery ignition system, and furthermore it has been found in some cases that it is preferable for electrical reasons also to provide the connection at or as near as possible to the source of generation of the current which in ignition systems is at the ignition coil. In accordance with our invention, the terminal connector is applied directly to the coil by means of a bus bar to which is electrically connected the terminal connector and the wire leading to the mechanical interrupter of the magneto or timer-distributor, in addition to the end or ends of the windings of the ignition coil. If an automatic grounding or disabling arrangement is provided, a spring or other device which may be used for the purpose is also electrically connected to the bus bar and preferably in such manner as to move automatically, when unrestrained by the terminal connector, into contact with a part of the housing or other grounded part of the magneto or coil.

The inventionwill be understood from the following disclosure in connection with the accompanying drawing illustrating the invention applied, as examples, to high tension ignition coils. In this drawing,

Fig. 1 is an end elevation, partly in section and partly diagrammatic, of the coil and the terminal connector, provided with automatic grounding means and shown in the normal operating position; Fig. 2 is a section on line 2-4 65 tube 2'! with its insert 28 inwardly to provide of Fig. 1; Fig. 3 shows a part oi Fig. 1 with the terminal connector partly removed and the coil disabled or grounded; Fig. 4 shows a side elevation of one end of the coil of Fig. i; and Fig. 5 shows another embodiment of the invention in which no grounding or disabling means are provided.

Referring to the embodiment of Figs. 1-4, the reference numeral i is a part of the magneto frame having stationary magnets like 2, laminated pole pieces 2 in magnetic contact therewith, and a stationary generating coil 4 having primary and secondary windings and a laminated core 5 bridging the pole pieces. The outer high tension terminal 6 of the coil is connected by the shrouded conductor 1 to the high tension distributor (not shown) of the magneto. One terminal of the primary winding of the coil is grounded on the core 5 in the well known way, and the other terminal 6 thereof, together with the inner terminal 8 of the secondary winding, is soldered as shown to the metal terminal plate to on the outer face of one of the insulatedend discs ll of the coil. To this plate Ill is mechanically and electrically fastened a bus bar I2 which is also mechanically fastened to but insulated from the core 5 and pole piece 3 by means of the screw i3 with its insulating bushing It. The other end of the coil core is mechanically and electrically fastened to the other pole piece 3 by the screw [5. Fastened electrically and mechanically to the bus bar by riveting is a wire terminal It for clamping therein by the screw II the insulated wire i8 leading to the live terminal of the grounded mechanical interrupter l9.

Riveted to the bus bar l2 at 20 is a fiat beryllium copper spring 2| having a curved end 22 and so stressed, when unrestrained, as to spring away from the bus bar into electrical contact with the inside of the frame i of the magneto as shown in Fig. 3. In line with this spring is a cable terminal generally designated 23 comprising a metal housing 24 screwed into a tubular projection 25 of the frame and having a terminal nut 26 screwed onto its outer end. Inside this housing is an insulating tube 21 having a metal insert 28 terminating in a threaded end on which is screwed a nut 20 carrying a helical contact spring Ill. The shielded cable it passes through the nut 26 and has its bared wires fastened in the insert 28 so as to be electrically connected to the contact spring 20. When compressed by the nut 28, the rubber grommet 3| seals the terminal nut and forces the insulating good electrical contact between the two springs and 2| and to force the latter against the bus bar I2 out of electrical contact with the grounded frame I, as shown in Fig. 1. Thus when the terminal connector 23 is assembled as shown in Fig. 1, electrical connection is maintained between the grounding switch 32 of the magneto, or other electrical device, and the bus bar I2, to which are electrically connected the live terminals 8 and 9 of the coil 4, and at the same time the spring 2| is held away from the frame I in its ungrounded position. The coil 4 may then be grounded at will by closing the switch 32. However, with switch 32 open or closed, whenever the terminal connector 23 is removed for inspection or repair purposes, the coil 4 is automatically grounded by the spring 2| and the magneto disabled or rendered electrically inoperative, and maintained in that condition until the connector is restored to its normal position.

Now referring to the embodiment of Fig. 5, the construction is identical except there is no grounding spring 2| of the former embodiment, and the terminal connector 33' contacts the bus bar 34 directly as shown. This then forms an electrical connector solely, and may be used for connecting a battery-excited vibrator 35 to the coil directly for supplying current impulses to the coil and the mechanical interrupter in electrical parallel to assist the magneto in starting the engine in the well known manner. Electrical devices other than vibrator 35, such as switches or starting magnetos, may be connected in the same way to the coil and interrupter in electrical parallel.

It will be apparent in both embodiments herein disclosed, that the coil 4 forms a unitary element for installation, replacement or repair, the bus bar I 2 or 34 being supported rigidly in relation to the coilby the mechanical connections between the bus bar and the terminal plate l0, and

the wire terminal I! being mechanically fastened to the bus bar, and the grounding spring 2|, where provided, being mechanically fastened to the bus bar also. The terminal plate I! is rigidly fastened mechanically to the end plate ll of the coil in any suitable way as by varnish and is held more securely in place by the soldering thereto of the ends 8 and 9 of the coil winding, as shown in Patent 2,259,229.

It will be understood that in the normal or installed position of either terminal connector 26 or 33 of the two embodiments, the spring thereof may be said to be detachably engaged mechaniciated with a mechanical interrupter of an ignition system, said coil having an insulated bus bar supported rigidly in relation to the coil, an insulated terminal plate which is mechanically fastened to the coil and which is electrically con nected to at least one live terminal of the coil and also to the bus bar, and a wire connector which is electrically connected to the bus bar and which is fastened to a wire leading to the mechanical interrupter; of a terminal connector ineluding a conductor mechanically and electrically engaged with the bus bar.

2. In combination with an ignition coil having a magnetic core and being associated with a mechanical interrupter of an ignition system, said coil having an insulated bus bar supported by but insulated from the core, an insulated terminal plate which is mechanically fastened to the coil and which is mechanically and electrically fastened to the bus bar, a wire connector which is mechanically and electrically fastened to the bus bar and which is fastened to a wire leading to the mechanical interrupter, and a housing; of a terminal connector which is detachably mounted on the housing and which includes a conductor detachably engaged mechanically and electrically with the bus bar. I

3. In combination with an ignition coil associated with a mechanical interrupter of an ignition system, said coil having an insulated bus bar supported rigidly in relation to the coil, an insulated terminal plate which is mechanically fastened to the coil and which is electrically connected to at least one live terminalof the coil and to the bus bar, a wire connector which is fastened to a wire leading to the mechanical interrupter and which is electrically connected to the bus bar, and a grounding spring mechanically and electrically fastened to the bus bar; of a terminal connector including a conductor detachably engaged mechanically and electrically with the spring and restraining the spring from a grounding position.

4. In combination with an ignition coil having a magnetic core and being associated with a mechanical interrupter of an ignition system,

cally and electrically with the bus bar I! or 34 5 whether or not a grounding spring is present.

While we have but shown two embodiments of our invention, it will be understood that many modifications are possible in construction and use within the broad interpretation of the appended claims. ignition system to which the invention is applied may be of the low tension or high tension type for any number of engine cylinders operating on any cycle and driven at any suitable speed ratio.

For instance, the magneto or battery;

Also the ignition system may be arranged for I single or double sets of sparkplugs in the engine cylinders. Furthermore, the terminal connector 26 or 33 may be of any suitable construction and may be used to connect any other suitable electrical device to the bus bar I! or 34 for any suitable purpose.

Having thus described our invention, what we I claim is:

said coil having an insulated bus bar supported by but insulated from the core, an insulated terminal plate which is mechanically fastened to the coil and which is mechanically and electrically fastened to the bus bar, a wire connector which is mechanically and electrically fastened to the bus bar and which is fastened to a wire leading to the mechanical interrupter, a grounding spring mechanically and electrically fastened to the bus bar, and a housing; of a terminal connector which is detachably mounted on the housing and which includes a conductor detachably engaged mechanically and electrically with the spring and restraining the spring from engagement with the housing.

5. As a unitary element for anignition system having a mechanical interrupter, an ignition coil, an insulated bus 'bar mechanically fastened to the coil, an insulated terminal plate electrically connected to at least one live terminal of the coil and also to the bus bar, a wire connector I which is adapted to be electrically connected to the bus bar and which is adaptedto beelectrically connected to a wire leading to the mechanical interrupter, and a grounding spring which is mechanically and electrically fastened to the bus bar and which when unrestrained is adapted to assume a grounding position away 1. In combination with an ignition coil assofrom the bus bar.

nausea 3 6. As a unitary element for an ignition system having a mechanical interrupter, an ignition coil having a magnetic core. a bus bar adapted to be mechanically fastened to but electrically insulated from the core, an insulated terminal I plate which is mechanically fastened to the coil and electrically connected to at least one live terminal of the coil and which is mechanically and electrically fastened to the bus bar, a wire 

